Catalyst for hydrotreating petroleum hydrocarbon oils and catalyst employed therein

ABSTRACT

The process comprises contacting a mineral lubricating oil distillate in a first reaction zone with a sulfactive hydrogenation catalyst in the presence of hydrogen and under hydrogenation and desulfurization conditions to produce a desulfurized product and contacting said desulfurized product in a second reaction zone with the catalytic composition of the invention in the presence of hydrogen and under selected conditions. The catalytic composition comprises a Group VIII noble metal deposited upon a large-pore-diameter alumina.

I United States Patent 1 1111 3,882,049

Bertolacini et al. May 6, 1975 CATALYST FOR HYDROTREATING 3,472,897 10/1969 Pryor et al, 252/466 PT PETROLEUM HYDROCARBON OILS AND 3,549,720 l2/l970 Wright et all 252/466 PT 3,6l5,207 10/1971 Lee 252/466 PT CATALYST EMPLOYED THEREIN 3,635,841 l/l972 Keith et al. 252/466 PT [75] Inventors: Ralph J. Bertolacini, Chesterton; 3,64 ,7 3/1972 aye v 252/466 PT Paul Donald Hopkins; Roland L Hayes .4 Menu, both of Hammond a of 3,669,904 6/1962 Cornelius 252/466 PT Ind.

. Primary Examiner-Arthur P, Demers [73] Asslgnee' Smndard Company Chlcago Attorney, Agent, or Firm-James L. Wilson; Arthur G. [22] Filed: June 12, 1973 Gilkes; William T. McClain [21] App]. No.: 369,402

Related US. Application Data {57] ABSTRACT [62] Division of Ser No 183 615 Aug 24 1971 The process comprises contacting a mineral lubricatabandone i ing oil distillate in a first reaction zone with a sulfactive hydrogenation catalyst in the presence of hydro- 52 C] 252/466 208/89; 208/2"); gen and under hydrogenation and desulfurization con- 208/264; 252/465 ditions to produce a desulfurized product and contact- 51 1m. 01 B0lj 11/08 Said desulfurized Product in a Sewn! reaction [58] Field of Search 252/466 PT Zone with the catalytic compflsition of the invention in the presence of hydrogen and under selected condi- [56] References Cited UNITED STATES PATENTS The catalytic composition comprises a Group VIII 3 161 605 12/1964 Beck et al. 252 466 PT noble metal depc'sited a large'pore'diamem 3,165,479 1/1965 Burk et a]. 252 466 PT alumina 3,393,148 7/l968 Bertolacini et al. 208/264 3,459,814 8/!969 Kouach et al 6. 252 466 PT 4 N0 D'awmgs CATALYST FOR HYDROTREATING PETROLEUM IIYDROCARBON OILS AND CATALYST EMPLOYED THEREIN CROSS-REFERENCE TO RELATED APPLICATION This application is a divisional application of copending application U.S. Ser. No. 183,6l5, filed on Sept. 24, I97] and now abandoned.

BACKGROUND OF THE INVENTION In the past, lubricating oils and derivatives therefrom have been refined by employing a finishing treatment using clay or a combination of sulfuric acid and clay. In many cases, the feedstock had been dewaxed and/or solvent extracted. Such finishing treatments provided a treated product that possessed improved color and odor and, in many cases, improved stability to light and oxidation. In general, stability to oxidation and to light has been maintained by the addition of one or more chemicals to the finished product. In recent years, the quality of lubricating oils has been improved by a finishing treatment comprising a relatively severe hydrogenation treatment.

One of the important applications of hydrotreating a lubricating oil distillate is the hydrotreating of mineral oils to produce white oils. A white oil is a highly refined lubricating oil fraction which has a colorless, water-white appearance. Such an oil must be colorless, odorless, and tasteless; and it must be essentially free of aromatic hydrocarbons. It must have a color of +30 Saybolt and must possess a low absorbence of ultraviolet light. Typical white oils may be used for cosmetics and certain medicinal purposes.

The hydrogenation treatment of a lubricating oil fraction to produce a white oil, in general, comprises a two-stage process. In the first stage of a typical process, the selected lubricating oil fraction is desulfurized over a sulfactive hydrogenation catalyst under relatively severe hydrogenation conditions, and the effluent from this first stage is contacted in a second stage with hydrogen under relatively mild conditions with a hydrogenation catalyst comprising a platinum group metal on a non-acidic or a weakly-acidic support.

Now there has been found an improved catalyst to be used in the second stage of such hydrofinishing processes. Moreover, it has been found that the process employing this improved catalyst provides superior white oils.

SUMMARY OF THE INVENTION Broadly, according to the present invention, there is provided an improved catalytic composition for the hydrotreating of a petroleum hydrocarbon oil to produce a colorless mineral oil, which catalytic composition comprises a Group VIII noble metal deposited upon a large-pore-diameter alumina having a surface area of about I50 square meters per gram to about 500 square meters per gram and an average pore diameter of about 100 Angstrom units (A) to about 200 A. The Group VIII noble metal may be present in an amount ofabout 0.l weight percent to about 2 weight percent, based on the weight of the catalytic composition. The preferred Group VIII noble metal is palladium.

In addition, according to the present invention, there is provided a process for the production of a colorless mineral oil. This process comprises contacting a mineral lubricating oil distillate in a first reaction zone with a sulfactive hydrogenation catalyst in the presence of hydrogen and under hydrogenation and desulfurization conditions to produce a desulfurized product and contacting the desulfurized product in a second reaction zone with the catalytic composition of the present invention in the presence of hydrogen and under selected operating conditions.

DESCRIPTION OF THE INVENTION According to the present invention, there is provided an improved catalytic composition for the hydrotreating of a mineral lubricating oil distillate to produce a colorless mineral oil. There is also provided a process for the production of a colorless mineral oil, which process employs as a catalyst the catalytic composition of the present invention.

The improved catalytic composition comprises a Group VIII noble metal deposited upon a large-porediameter alumina having a surface area of about 150 square meters per gram to about 500 square meters per gram and an average pore diameter of about [00 to about 200 A.

One of the components of the catalytic composition is a Group VIII noble metal. The Group VIII noble metals are palladium, platinum, rhodium, iridium, ruthenium, and osmium. The preferred Group VIII noble metal is palladium.

The other essential component of the improved catalytic composition of the present invention is a largepore-diameter alumina. The average pore diameter of the alumina should be within the range of about I00 to about 200 A. Suitably, the average pore diameter should be at least A. Preferably, the average pore diameter of the alumina that is employed in the catalytic composition of the present invention is at least A. The surface area of this large-pore-diameter alumina should be within the range of about I50 square meters per gram to about 500 square meters per gram. Suitably, the surface area is at least 200 square meters per gram. Preferably, the surface area is at least 300 square meters per gram.

The catalytic composition of the present invention may also contain minor amounts of other components which do not adversely affect the performance of the catalyst for the hydrogenation and finishing of mineral lubricating oil distillates. An example of such a component is silica, which may be present in an amount of no more than 5 weight percent and which may provide a stabilizing effect upon the catalyst.

Suitable aluminas can be purchased from manufacturers of catalysts. For example, Nalco HF-type aluminas are available from the Nalco Chemical Company. These HF-type aluminas can be obtained with pore volumes varying from as low as 0.54 cc per gram to as high as 2.36 cc per gram and a corresponding average pore diameter within the range of about 72 to about 305 A. A typical sample of Nalco I-IF-type alumina was found to have a surface area of 348 square meters per gram and an average pore diameter of about I l 2 A. Therefore, those Nalco HF-type aluminas which have the desired physical properties are suitable for use as the support of the catalytic composition of the present invention.

In addition, suitable aluminas can be obtained from the American Cyanamid Company. For example, a typical sample of American Cyanamid's Aero Extrudate 100, Sample No. 2234-2, was found to have a calculated average pore diameter of I38 A, a surface area of 238 square meters per gram, and a pore volume of 0.82 cc per gram. It contained 6.2 weight percent volatiles, 0.3 weight percent silica, 0.03 weight percent sodium oxide. and 0.03 weight percent iron. The extrudates had an average length of 0.l6 inch and a diameter of 0.064 inch.

The catalytic composition of the present invention may be prepared by several methods. The Group Vlll noble metal may be added in the form of a soluble salt of that Group Vlll noble metal to either a hydrosol or hydrogel of the alumina and the resulting composite subsequently blended, dried, and calcined. As an alternative, either extrudates or pellets of the alumina may be impregnated with an aqueous solution of the selected Group VIII noble metal. When the Group Vlll noble metal is palladium, its salts may be any commercially-available salt or palladium metal solubilized by aqua regia. The impregnated composite may then be dried and calcined.

The Group Vlll noble metal is present in an amount within the range of about 0.1 weight percent to about 2 weight percent, based on the weight of the catalytic composition. Preferably, no more than l weight percent of the Group Vlll noble metal is employed.

According to the present invention, there is provided a process for the production of a colorless mineral oil. This process comprises contacting a mineral lubricating oil distillate in a first reaction zone with a sulfactive hydrogenation catalyst in the presence of hydrogen and under hydrogenation and desulfurization conditions to produce a desulfurized product and subsequently contacting said desulfurized product in a second reaction zone with the catalytic composition of the present invention in the presence of hydrogen and at a temperature of at least 450F., a liquid hourly space velocity (LHSV) of about 0.25 to about 1 volume of hydrocarbon per hour per volume of catalyst, and a hydrogen addition rate of about 1,500 standard cubic feet of hydrogen per barrel of hydrocarbon (SCFB) to about 7,000 SCFB, and a hydrogen partial pressure of at least 500 psig. The catalytic composition of the present invention, as described hereinabove, comprises a Group VIII noble metal deposited upon a large-pore-diameter alumina having a surface area of about I50 square meters per gram to about 500 square meters per gram and an average pore diameter of about l to about 200 A. The maximum temperature that is employed in the second reaction zone of this process is 500F. and the maximum value of the hydrogen partial pressure in this second reaction zone is 2,500 psig.

The catalyst that is employed in the first reaction zone of the process of the present invention is a sulfactive hydrogenation catalyst. Examples of such a catalyst are (l) a catalyst comprising nickel and molybde num, either in the form of the elements or compounds thereof, deposited upon a non-acidic support or a weakly-acidic support, such as alumina, and (2) a catalyst comprising cobalt and molybdenum in the form of elements or as compounds thereof, deposited upon a non-acidic or weakly-acidic catalyst support material. It is contemplated, according to the present invention, that such sulfactive hydrogenation catalyst could comprise one or moe of other Group V] and Group VIII metals, or their compounds, on selected non-acidic or weakly-acidic catalyst supports. Such supports include alumina, silica, and activated carbon.

The operating conditions that are employed in the first reaction zone of the process of the present invention comprise an elevated pressure of up to 5,000 psig, a temperature of about 600to 1,000F., a LHSV as large as 5 volumes of hydrocarbon per hour per volume of catalyst and a hydrogen circulation rate as high as 25,000 SCFB.

Any mineral lubricating oil distillate may be treated in the process of the present invention. The feedstock might be a light lubricating oil, or it could be a heavy lubricating oil. The viscosity of the oil could have a value as low as about 40 Saybolt seconds at F. On the other hand, the feedstock can have a viscosity as high as SAE 60. In general, the feedstock has been dewaxed and/or solvent extracted. Solvents employed to preferentially dissolve aromatic hydrocarbons include phenols, furfurals, liquid S0 nitrobenzene, and dimethyl formamide.

The product that is obtained from the process of the present invention is a colorless water-white oil and has a color of +30 Saybolt and possesses a low absorbence of ultraviolet light. The UV analysis, pursuant to the Food and Drug Administration specification, can have a maximum value of 0.1. The product, when submitted to the test for readily carbonizable substances, which test is identified hereinbelow, can have a maximum USP-Acid Test value of 2.5

In a preferred embodiment of the process of the present invention, a solvent extracted SAE-40 oil is contacted in a first reaction zone with a catalyst comprising about 2 weight percent nickel oxide and about 15 weight percent molybdenum trioxide on a catalytically active alumina. Hydrogen or hydrogen-containing gas is added to this first reaction zone and the operating conditions are such that desulfurization takes place. The effluent from this first reaction zone is separated into a liquid product and gaseous product, the latter of which contains any hydrogen sulfide and ammonia formed during the hydrogen treating in the first reac tion zone. The desulfurized hydrocarbon stream, free of hydrogen sulfide and ammonia, is then passed into a second reaction zone and is contacted therein with a catalyst comprising 0.5 weight percent palladium supported on a large-pore-diameter alumina having a sur face area of about 347 square meters per gram and an average pore diameter of 1 l2 A. The operating conditions in this second reaction Zone comprise a temperature of about 475F., a LHSV of about 0.25 to about 0.5 volume of hydrocarbon per hour per volume of catalyst, a hydrogen partial pressure of about 1,600 psig, and a hydrogen circulation rate within the range of about 1,500 SCFB to about 7,000 SCFB. The effluent from the second reaction zone is treated to remove the liquid effluent from the gaseous material. The liquid effluent, that is, the refined mineral lubricating oil distillate, possesses a Saybolt color of +30, a USP Acid Test value that is no greater than 2.5 and a FDA-UV Absorbence value that is no greater than 0.l.

The above preferred embodiment and the following examples are presented for purposes of illustration only and are not intended to limit the scope of the present invention.

EXAMPLE I A typical embodiment of the catalytic composition of the present invention was prepared. A 4,4-gram portion of (NH Pd (NO was dissolved in hot boiling aqua regia and evaporated to a dry residue. This residue was then re-dissolved in ml of concentrated nitric acid. Sufficient distilled water was added to make 500 ml of solution, which was heated until the residue was completely dissolved. The resultant solution was then cooled to room temperature and was used to impregnate 500 grams of freshly calcined Cyanamid Aero I00 large-pore-diameter alumina. This alumina had been calcined in air at a temperature of about I,000F. for about 3 hours. The impregnated material was then dried in air at 250F. for 3 hours and was calcined for 6 hours in air at a temperature of 1,000F. The air flow rate employed during the drying and calcining was about 1.5 cubic feet per minute. The catalyst was prepared to contain about 0.5 weight percent palladium.

EXAMPLE II Several mineral lubricating oil distillates were desulfurized over a catalyst comprising nickel and molybdenum compounds on alumina under relatively severe hydrogenation conditions. These feedstocks are identified hereinafter as Feed A, Feed B, Feed C, and Feed D. Feed A was a solvent-extracted, dewaxed SAE-IO oil; Feed B, a 1:3 blend of a mildly hydrofinished solventextracted, dewaxed SAE-40 oil and a solventextracted, dewaxed SAE-20 oil; Feed C, a solventextracted, dewaxed SAE-SW oil; and Feed D, a distillate boiling in the range of 495 to 650F.

The product that was obtained from each of these hydrogenation and desulfurization treatments was then individually hydrogenated in the presence of the catalytic composition that was prepared in Example I under the following hydrogenation conditions: a hydrogen partial pressure of 1,600 psig, a LHSV of about 0.25 to about 0.5 volume of hydrocarbon per hour per volume of catalyst, a hydrogenation circulation rate of 1,500 SCFB to 7,000 SCFB, and a temperature within the range of 450 to 500F. Therefore, each of the starting materials was hydrofinished according to the process of the present invention.

Each of the products was tested for carbonizable substances, color, presence of polynuclear compounds, and odor.

The test for carbonizable substances, identified as the USP Acid Test, is described in both the Regulations for Mineral Oil in the UNITED STATES PHARMACO- PEIA XVIII (1970), pp. 436-437, and the Regulations for light Mineral Oil in the NATIONAL FORMU- LARY XIII (1970), pp. 461-462. This test was modified by measuring the color of the acid extract by the ASTM color method, rather than by comparing the color to the suggested standard color. The ASTM color method has ASTM designation D 1500-64 and IP designation 196/66. The approximate ASTM color value of the standard color referred to in USP Acid Test is 2.5. Therefore, to pass the test, the color of the acid extract could not be more than 2.5 ASTM.

The test for the presence of polynuclear compounds is identified as the FDA ultra-violet adsorption test and is described in paragraph 121.1 146 of the FDA REGU- LATIONS and is identical to the Limit of Polynuclear Compounds in the Regulations for Mineral Oil in the UNITED STATES PHARMACOPEIA XVIII (1970), pp. 436-437. The absorbence of the standard was determined to be about 0.3. Therefore, to pass the test, the mineral oil must have a maximum absorbence of 0.1 in the 260 mu to 350 mp range.

The color of each petroleum product was tested pursuant to the ASTM Standard Method of Test for Saybolt Color of Petroleum Products, which method has ASTM Designation D-l56-64 and is identified hereinafter as Saybolt Color.

The hydrofinished product must be colorless.

The Solid Paraffin Test is described in both the Regulations for Mineral Oil in the UNITES STATES PHAR- MACOPEIA XVIII (1970). pp. 436-437, and the Regulations for Light Mineral Oil in the NATIONAL FOR- MULARY XIII (1970), pp. 461-462.

The results of the various tests are presented hereinbelow in Table I. Please note that each of the products passed all requirements, with the exception of the product from Run No. 2, which product failed the Solid Paraffin Test. This was the result of the high wax content of that particular feed.

TABLE I PROPERTIES OF PRODUCTS Run No. l 2 3 4 Feed A B C D Color, Saybolt +30 +30 +30 +30 Carbonizable substances,

USP pass pass pass Odor pass pass pass pass UV Absorbence (260-300 mg) 0.02 0.01 Unsulfonated Residue, 99.0 98.4 100.0 Solid Paraffin, USP pass fail pass EXAMPLE III A catalyst containing a typical prior-art alumina having smaller pore diameters was prepared. A S-pound batch of Grade alumina was blended with a sufficient amount of distilled water to provide an alumina slurry which had a water content of 41 percent. This alumina, prior to blending, was in a finely divided state and was capable of passing through a 250-mesh screen (U.S. Series). It was obtained from the Filtrol Corporation. The resulting blend was extruded, dried in air at a temperature of about 250F., and calcined in air for 3 hours at a temperature of 1,000F. The finished alumina was in the form of 1/1 6-inch extrudates.

A 696-gram portion of these I/l6-inch extrudates was impregnated with an aqueous solution prepared by dissolving 7.6 grams of Pd(NO in 674 milliliters of distilled water containing 5 milliliters of concentrated nitric acid. The impregnated material was dried in air overnight at a temperature of approximately 250F. and was calcined subsequently in air for 3 hours at a temperature of l,000F.

This catalyst, which was prepared to contain 0.5 weight percent palladium, is hereinafter identified as Catalyst B. The finished catalyst was found to have a surface area of 225 square meters per gram, a pore volume of 0.47 cc/gram, and a calculated average-porediameter of 84 A.

EXAMPLE IV An embodiment of the catalytic composition of the present invention was prepared by the American Cyanamid Company. This catalyst was manufactured by using Cyanamid Aero large-pore-diameter alumina. The finished catalyst contained 0.49 weight percent palladium and had a surface area of 240 square meters per gram, a pore volume of 0.82 cc/gram, and

a calculated average-porediameter of 137 A. This catalyst is hereinafter identified as Catalyst C.

EXAMPLE V This example was designed to demonstrate the improved presently-disclosed process for hydrotreating a mineral lubricating oil distillate over a process comprising two stages and employing as the catalyst in the second stage a catalyst comprising alumina having a smaller-pore-diameter alumina.

A two-stage hydrogenation process was simulated in each of these tests. In each instance, the first stage comprised hydrotreating solvent-extracted dewaxed SAE-20 oils and solvent-extracted, dewaxed and, in some cases, mildly hydrofinished SAE-40 oils in a first reactor under relatively severe hydrogenation conditions in the presence of a commercial sulfactive hydro treating catalyst. This catalyst was a commercial Cyanamid HOS-3A catalyst comprising nickel and molybdenum on l/l6-inch extruded alumina.

The solvent-extracted hydrocarbon stream was mixed with hydrogen and the mixture was introduced into the top of the reactor and was permitted to pass down through the catalyst bed. The reactor was held in the unit in a heating block that was electrically heated. The effluent was cooled and passed through a .lerguson separator and stripping column. The liquid effluent from this first reactor was composited and the resulting composite was found to have a gravity at 60F. of 31 .5 API. a viscosity at lF. of 300 SUS, a sulfur level of 3 ppm, a Saybolt color of +20, a FDA UV Test value of 2.82, and a USP Acid Test value that was greater than 8 ASTM. This severely hydrogenated hydrocarbon stream constituted the intermediate product in the simulated two-stage processes of this example. This intermediate product had a low sulfur level and a relatively low aromatic content and was subsequently employed as the feed to the second stage of each of the two-stage processes.

For the first stage of each process of this example, 600 cc of catalyst were employed. The reactor was fabricated from a stainless steel pipe having an inside dilyst for 2 hours at a temperature of 400F. The temperature was then raised to 700F. over a period of l hour and the sulfiding was continued for several more hours. The flow rate of the hydrogen sulfide-hydrogen gas mixture was approximately 1 cubic foot per hour per pound of catalyst.

For the second stage of each process tested in this example, the intermediate product, that is, the liquid effluent from the first stage. was mixed with hydrogen and the resulting mixture was introduced into the top of the secondstage reactor. This reactor may be described as a reactor identical to that employed in the first stage. However, only 400 cc of catalyst were employed in the second-stage reactor and the length of the reactor bed was approximately l4 inches. The effluent from the reactor was cooled and passed sequentially through a .lerguson separator and then to a stripping column. The product obtained from the stripper was collected in a nitrogen-blanketed product receiver.

The operating conditions in the second-stage reactor for Catalyst 8 included a temperature of 475F., a hydrogen partial pressure of [,600 psig, a LHSV of 025 volume of hydrocarbon per hour per volume of catalyst, and a hydrogen-addition rate of 6,400 SCFB. The operating conditions employed in the second reactor for Catalyst C included a temperature of 475F., a hydrogen partial pressure of 1,600 psig, a LHSV of 0.27 volume of hydrocarbon per hour per volume of catalyst, and a hydrogen-addition rate of 6,000 SCFB.

Once-through hydrogen was employed for each stage of each of these processes.

Various tests were performed on the liquid products obtained from the second stage of each of these two processes. The results of these tests are presented in Table [I hereinbelow. It was found that the products obtained from the process employing Catalyst B as the second-stage catalyst contained traces of catalyst fines. Therefore, these products were filtered through a l.2p. millip0re" filter. The USP Acid Test value is provided for each of these products prior to and subsequent to the filtering treatment.

TABLE ll PROPERTIES OF PRODUCTS Znd-stagc Catalyst Time on Stream,

hrs.

USP Acid Test USP Acid Test (filtered product FDA-UV Absorbcncc (260-350 my.) Color. Saybolt ameter of 1.5 inches. The catalyst was supported by a layer of 6-mm glass beads on a l0mesh stainless steel screen. The screen was located 4% inches from the bottom of the reactor. The screen and layer of beads occupied approximately nine-sixteenths-inch of the reactor length. The catalyst bed occupied approximately 20% inches of the reactor length. The space in the reactor above the catalyst bed contained 6-mm glass beads to within an inch of the top closure.

The catalyst in this first-stage reactor was sulfided by passing a mixture of eight volume percent hydrogen sulfide and 92 volume percent hydrogen over the cata- These data indicate that a product that was obtained from the embodiment of the process of the present invention provided a USP Acid Test value which was superior to that obtained from the process employing Catalyst B as the second-stage catalyst. In fact, the USP Acid Test values obtained with the product of this latter process appear, in general. not to pass the specificationv It may be concluded from the results obtained in this example that the embodiment of the process of the present invention, that is, the process employing Catalyst C, provides an improved product relative to the product obtained from the process employing Catalyst B as the second-stage catalyst. at typical two-stage hy- 2. The catalytic composition of claim 1 wherein said drogenation process. Group VIII noble metal is present in an amount of What is claimed is: about 0.1 weight percent to about 2 weight percent, 1. An improved catalytic composition for the hydrobased on the weight of said catalytic composition.

treating of a petroleum hydrocarbon to produce a col- 5 3. The catalytic composition of claim 1 wherein said orless mineral oil, which catalytic composition consists Group VIII noble metal is palladium essentially ofa Group VIII noble metal deposited upon 4. The catalytic composition of claim 3 wherein said a large-pore-diameter alumina having a surface area of palladium is present in an amount of about 0.1 weight about 200 square meters per gram to about 500 square percent to about 2 weight percent, based on the weight meters per gram and an average pore diameter of about 0 of said catalytic composition.

lAto about 200 A. 

1. AN IMPROVED CATALYTIC COMPOSITION FOR THE HYDROTREATING OF A PETROLEUM HYDROCARBON TO PRODUCE A COLORLESS MINERAL OIL, WHICH CATALYTIC COMPOSITION CONSISTS ESSENTIALLY OF A GROUP VIII NOBLE METAL DEPOSITED UPON A LARGE-PORE-DIAMETER ALUMINA HAVING A SURFACE AREA OF ABOUT 200 SQUARE METERS PER GRAM TO ABOUT 500 SQUARE METERS PER GRAM AND AN AVERAGE PORE DIAMETER OF ABOUT 120 A TO ABOUT 200 A.
 2. The catalytic composition of claim 1 wherein said Group VIII noble metal is present in an amount of about 0.1 weight percent to about 2 weight percent, based on the weight of said catalytic composition.
 3. The catalytic composition of claim 1 wherein said Group VIII noble metal is palladium.
 4. The catalytic composition of claim 3 wherein said palladium is present in an amount of about 0.1 weight percent to about 2 weight percent, based on the weight of said catalytic composition. 